- Tytuł:
-
Sposoby określania miąższości kłód brzozy brodawkowatej (Betula pendula Roth)
Methods for determining the volume of silver birch (Betula pendula Roth) logs - Autorzy:
-
Bruchwald, A.
Dmyterko, E.
Witkowska, J.
Jodłowski, K. - Powiązania:
- https://bibliotekanauki.pl/articles/986659.pdf
- Data publikacji:
- 2018
- Wydawca:
- Polskie Towarzystwo Leśne
- Tematy:
-
lesnictwo
brzoza brodawkowata
Betula pendula
klody odziomkowe
klody srodkowe
miazszosc klod
metody obliczen
log volume
two−sectional equations
middle cross section equations
empirical equations - Opis:
- The purpose of the research was to develop and evaluate the accuracy of various methods for determining the volume of the butt−end (from 0 to 6 m) and middle (from 6 to 12 m) logs of silver birch. The material was collected on 84 samples plots established throughout Poland. On each plot, 2 to 10 trees (722 in total) were felled and measured using a cross−section method. The average age of the measured trees ranged from 22 to 97 years, the average diameter at the breast height from 7.0 to 39.6 cm, and the average height from 8.1 to 31.2 m. We tested 4 methods for log volume determination. Two can be used for individual logs and two for stacks. In method 1 one measures the log length and diameter under bark at a distance of 1 meter from the butt−end and at half the length of the remaining part of the log. The log volume is defined by a two−sectional formula based on the middle cross−section (eq. 1). The average error for that method is close to zero, regardless the log length (tab.). In method 2, two−sectional formula of the middle cross−section was used with the diameter in the middle of each section calculated from the developed regression models based on the log length and diameter under bark at the top end. For both logs the error of volume calculation is small, especially for the middle one (tab.). Method 3 defines the log volume using the middle cross−section formula, which requires log length and diameter at half of the length. For the butt−end log, the volume has a systematic negative error, exceeding –5%. For the middle log, the formula is characterized by high accuracy. Method 4 is also based on the middle cross−section formula, but the diameter up to half the length is calculated from empirical formulas based on the log length and diameter under bark at the top end (eq. 5c and 6c). The accuracy of this method is close to the accuracy of method 3 (tab.). To determine the log volume in inaccessible places, method 2 can be recommended. The corresponding diameter is calculated from the regression equations. This method can also be used when the measurement places are accessible, which unifies the birch log measurement methods. However, determination of birch logs volume based on the commonly used middle cross−section formula should not be applied as for the butt−end log this method produces too large negative error, additionally increased by the rounding down the diameter measurement.
- Źródło:
-
Sylwan; 2018, 162, 06; 443-451
0039-7660 - Pojawia się w:
- Sylwan
- Dostawca treści:
- Biblioteka Nauki
Artykuł